Reproducing the Census - 1841 Census Image Quality
Review by David Tippey
“S&N's Greyscale images
offered 30% more readable pages”
of the original copies of the 1841 census enumerators
books held at the National Archives is poor. The entries
were mainly written in pencil on what is now very discoloured
paper, so it is no wonder that the filmed images have
taxed the reading abilities of family historians ever
since they became available.
companies making scanned images of the census available
on CD, we can now puzzle over census images at our leisure,
but the particular problems presented by the faded 1841
census books have proved more difficult to transfer
it to CD and retain even the moderate legibility available
on the microfilm copies.
The standard approach to scanning other
census years has been to produce the images in Black
and White only from diazo microfilms provided by the
National Archives. This has proved to produce perfectly
acceptable images, however when applied to the 1841
census the results are nowhere near as good. I was extremely
disappointed by the first 1841 B&W census CD images
I viewed for Yorkshire. Many of the pages I knew to
be readable on the local library's filmed version were
illegible. on the CD images
The alternative to using B&W images
scanned from diazo films is to take the more expensive
silver halide film from the National Archives, which
holds greater detail than the diazo films we are used
to seeing in record offices, and scan the page images
in Greyscale to capture all the available detail.
This is what S&N
Genealogy Supplies have done and having
tried their new Greyscale scanned images of my local
area, I found that once again I was able to discern
the writing on these familiar pages. However it may
have just been luck that those particular books were
better, so I decided to delve a litlle deeper into the
Yorkshire images and try to make a more comprehensive
The problem with greyscale images
from the publisher's point of view is that the file
sizes are much greater, which is reflected in the number
of CDs in the sets, making them more expensive to publish.
The poor quality of the pages also means that many of
them have to be rescanned at different settings to capture
the maximum detail. The greyscale images of the 147
Yorkshire Pieces HO 107 /1210 - 1357 fill a massive
44 CDs, whilst the B&W images covering the same
Piece numbers fit on just eight discs. However those
larger file sizes should in theory manage to capture
every little bit of available detail from the films,
optimising their readability.
My overall impression of the new S&N
CDs was that the greyscale images were much more readable.
This didn't mean that it was all legible though, some
pages still had unreadable areas. This is unavoidable
given the condition of the originals and the National
Archive films. I thought I should be a little more scientific
about my comparison, but there was no way I could compare
every enumerator's book in all the 147 Pieces for Yorkshire!.
My solution was to take an enumerators book at random
from every Piece with a number ending in zero, in the
hopes of achieving a reasonably representative sample.
This sampling method seemed to work as the resultant
books contained examples of both the best and poorest
examples I had come across.
I then viewed every page in both sets
of books and noted whether it was fully readable, sometimes
with difficulty, or had any portions that couldn't be
made out with any certainty. In some cases this was
the entire page, but in the main it was only a portion
of a page image. Having gone through both the B&W
and Greyscale images I found that the S&N greyscale
images offered over 30% more fully readable pages than
the B&W images. However this percentage increase
in full readable pages doesn't fully reflect the fact
that the Greyscale page images, mostly suffered from
small areas of poor clarity, whilst on many of the B&W
images, the areas were generally much larger.
Unless the National Archives could re-film
the census using better technology, we have to accept
that the 1841 census is always going to give researchers
problems, whether using microfilm or digitised CD images.
However I am totally convinced that the greyscale images
produce far more readable data than B&W images of
the same material. Given the choice between B&W
or Greyscale images of the 1841 census, I would certainly
choose the latter as in my opinion the greyscale images
offer the best of a bad census.
The Yorkshire Census and other census sets are available from GenealogySupplies.com.
“S&N's greyscale images offered
30% more readable pages”
David Tippey is well known writer on genealogy
and computer issues. whose work appears regularly in Family History
Monthly and Your Family Tree, as well contributing to a wide range
of other magazines and journals including Family Tree, Computers
in Genealogy, Internet and Broadband Advisor and the Family and
Local History Handbook.